Vascular Plants of North Carolina
Account for Hemlock Water-parsnip - Sium suave   Walter
Members of Apiaceae:
Only member of Sium in NC.
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Section 6 » Order Apiales » Family Apiaceae
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DistributionScattered over most of the Coastal Plain and the Piedmont. A few records for the foothills and edge of the southern Blue Ridge (Buncombe and Henderson counties).

This is a very wide-ranging species from coast to coast, but occurs south mostly to NC and MO, with more scattered records to northern FL and central TX.
AbundanceUncommon to infrequent in the lower Coastal Plain; generally uncommon and local in the eastern and central Piedmont and western Coastal Plain, but very rare in the Sandhills region and the western Piedmont/Mountains.
HabitatThis is a wetland species found in marshes, openings in swamps or bottomlands, and damp ground along creeks -- usually in partly shaded places.
PhenologyBlooms from June to August, and fruits from August to October.
IdentificationThis is a quite robust species with a stout and usually ridged stem, growing to 4-6 feet tall. It has alternate leaves, quite large, about 6-10 inches long, but pinnately divided into about 11-15 narrow, lanceolate leaflets. (Basal leaves are pinnate but may have a different shape.) Each leaflet is about 4 inches long and 3/4-inch wide, characteristically very finely and evenly serrated on the margins. The upper leaves are similar but much smaller. Though the terminal and lateral umbels of white flowers are rather similar to many other umbel species, the terminal umbel stalk is quite thick; most others in the family have rather slender stalks to the umbels. This species is usually readily identified in vegetative condition: a very robust species with a thick and ridged stem; once-pinnate leaves with narrow leaflets (somewhat like a few hickory species); and very evenly and finely serrated margins to the leaflets.
Taxonomic CommentsNone

Other Common Name(s)Water-parsnip, Tall Water-parsnip
State RankS3S4
Global RankG5
State Status
US Status
USACE-agcpOBL link
USACE-empOBL link
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B.A. SorrieMountains, Suches, GA, July 2015. Photo_non_NCPhoto_non_NC
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